Sobrevivência de escleródios de Sclerotinia sclerotiorum em solo, com aplicação de Clonostachys rosea

• Autor(a) principal: Chaves, Eugênio
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4398
• topic: Mofo branco; Controle biológico; Manejo; White mold; Biological control; Management; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

Sclerotinia sclerotiorum causes white mold, stem rot, watery rot and white rot disease in many important crops such as bean, soybean, cotton, tomato, and pea. The pathogen produces sclerotia that can survive in the field for several years, which hinders white mold control. In the perspective of assessing biocontrol in the management of the disease, we tested the efficiency of Clonostachys rosea in parasitizing sclerotia of the pathogen and reducing their viability. Thus, we studied in vitro the survival of sclerotia either dormant or conditioned to myceliogenic germination in soil samples that were untreated, pasteurized, or autoclaved, at different levels of both moisture and temperature, and infested with varying conidia concentrations of C. rosea. Temperature, moisture, stages of sclerotia, and conidia concentration did not affect the germination of sclerotia. Clonostachys rosea inhibited germination of sclerotia only in the autoclaved soil. Moisture, temperature, and conidia concentration had no effect in the recovery of C. rosea from soil. Although C. rosea have not affected the viability of sclerotia of S. sclerotiorum in untreated and pasteurized soils, it markedly reduced sclerotia viability in the autoclaved soil. The low competitiveness of C. rosea, and consequently its low efficiency in parasitism, is credited to the absence of external nutrient sources to support its establishment in both untreated and pasteurized soils. New studies to evaluate the effectiveness of these sources, particularly in soils under natural conditions, are suggested.